This invention relates generally to the transmission of data and, more specifically, to the transmission of data from a sensor on a rotating blade to a control system.
Wind turbines are increasing in size and capacity to meet increased electrical energy demands. To increase energy output, known rotor blade lengths have been increased, while the weight of known rotor blades has been decreased. As a result of the increased blade lengths and reduced blade weights, rotor blades may be subject to greater deflection forces and, thus, may be at a greater risk of blade stall, mechanical fatigue, and/or blade crash.
Blade stress is a function of temperature and pressure, among other things. A blade crash is a catastrophic failure that can sometimes occur on a wind turbine. A blade subject to blade crash can actually disintegrate and fall from a wind turbine. As such, to increase the awareness of potential blade problems, it is desirable to measure blade parameters while the blade is rotating. For example, known wind turbines include sensors for detecting rotor blade deflection. Such sensors are typically mounted on the rotor blades. A sensor can be wired to a blade, but since the blade is rotating, retrieving data with a wired connection is generally difficult. Communication signals and/or power cables must be provided across a pitch axis of the rotor blades. As such, known wind turbines utilize, for example, slip ring methods to bring the communication or power cables from the rotor blade to the hub. However, such techniques increase assembly and maintenance time, and increase the complexity of collecting real-time data of temperature, strain, and/or pressure.